Die for stamping out blanks, more particularly for leather goods



F. MERTINZ Dec. 10, 1929.

D IE FOR STAMPING OUT BLANKS, MORE PARTICULARLY FOR LEATHER GOODS Filed Feb. 8, 1921 both faces of the core.

. detached from the core.

of the plane of the cutters.

Patented Dec. 10, I929 Ens FRANZ MERTINZ, or vrnivivanusrnm DIE son STAMPING ourBLAnKs, Moun- PARTICULARLY on LEATHER, oons Application filed February 8, 1927, Serial No. 186,783, and in Austria May 18, 1926.

This invention relates to dies for stamping metal or the like, around the peripheral surface of which band-shaped cutters are fixed by means of screws in such a manner that 7 their cutting edges protrude beyond one or In using dies of this kind, they are laid on the leather or the like and are operated by the core being given a blow with a hammer or placed under the plunger of a press.

Such dies have various drawbacks which render themless durable, detrimentally affect the accuracy of their shape and make them unreliable in operation. These properties are, however, indispensable in view of the present great variety and complicated form of the leather'blanks to be stamped out, more particularly for shoe uppers. Thus, for instance, the screws connecting the cutters with the core take up the force of the blow exerted on the latter, so that the connection may easily becme loosened and the cutters become For avoiding these drawbacks, according to the present inven tion the cutters are supported on the core by means of pieces of any suitable shape and made in any suitable manner projecting out In order to avoid the use of the not very reliable screw connection the cutters are fixed to the core by means of bolts having no thread and attached to the core means of transverse pins. Nhere the core has narrow (tongue-like) parts, the dangers referred to are still greater and for this reason at such places the cutter is fixed by fixing means extending right through.

Further improvements relate to the cutters, the core, the elastic members releasing the stamped out blank from the core, and the punch of the press.

In the accompanying drawing a constructional example of the die according to the present invention is shown,

Figure 1 being a plan view,

Figure 2 a section on A-B of Fig. 1, partly in elevation,

Figure 3 a portion of the core with the cutter in vertical section, 1

Figure 4 a section on J,K of Fig. 3, Figure 5 a section on C, D of Fig. 1, Figure 6 a section on G, H of Fig.5, and Figure 7 a section on E, F'of Fig. 1, to an enlarged scale. i

The die consists of a core 1 which has the form of the leather blank to be stamped out and preferably consists of superposed pieces of veneer 2 glued together. Around the periphery of the said core band-shaped, flexible cutters 3 are so fixed that for instance they have their cutting edges 3, 3 projectin beyond each face of the core.

In order thatthe means 4 for fixing the cutters to the core shall not be subjected to stressing, when the die is in use, tongues 5 are for instance stamped out of the cutters and bent over, which in the form'of projections out of the plane of the cutter rest on the two faces of the core, preferably being let into the same. For this purpose the core is provided at suitable places with corresponding depressions 6. The stamping out and bending over of the tongues 5 may for instance be effected by subjecting the bandshaped cutters to a rapid local treatment with a hotjet of flame. The projections 5 may also be fixed in a suitable manner to the cutters 3 and may be embedded within the core, as shown by way of example in Figs. 3 and 4:, which represent a combination of the two improved forms. Y

Instead of the cutters 3 being 'fiXed to the core 1 by means of screws (wood screws) they may be fixed by means of threadless bolts 4 (Figs. 1 and 5) which are fixed to thecore l by transverse pins 7 extending through them.

The bolts may be given any suitable crossthrough the core, such as .rivets 9 screws or the like, which clamp two parts of the cutter and thecore lying between them to ether.

neer glued together, which is to be recom- V The rigidity of the cutter and -isconnection to the core is the greater, the smaller the number of pieces from which the whole cutter is put togetheiz For thisreason. the cutter is bent round more or less sharp edges (as for instance at 10 in Fighl), so that a single band-like cutter 3. extends right round the core, the connection of which with the core is thus made more simple. The cutter is closed at a single point only by mea-n-sof an angle piece 11 (Fig; or the like; v

When the core I is built up of'pi-eces 0t vemended on account of the great rigidity and the absence of liability towarp and the small- "er thickness of the core thus made possible,

it is advisable to secure the layers from be- ;coming detached from one another by the provision of screws 12, 13 (Figs. land 2) which are screwed into'the. core from both faces of the same, preferably staggered with respect to one another and overlapping each other in the transverse directiorrof the core.

For releasing. the stamped out leather blanks or the like fromthediecutter, elastic discs or cylinders for instance of rubber, have hitherto beenfixed to the faces of the core by Y formed.

means of sunk screws, whereby they are de- According tothe present invention elastic members-14, (Figs. 1 and 2) of substantially hemispherical shape are used, the entire base of which is sunk in depressions 15' in the core and which are fixed to the core by means of screws 16 which are sunk in the said meminto the blank, when it is being stamped out.

According to the present invention a yielding punch is provided; As shown in Fig. 7 a smooth sleeve 19 (i. e. asleeve having no projecting parts) contains the stamp 2-0 and can simply be slid into a hole in the core The punch acts on the blank of the pressure which is independent of the stamping pressure and-which corresponds to the strength of p the spring, so that the blanks are not liable to be damaged, which is of special importance in the case of fine leather.

What I claim is:

I. A die for stamping out blanks, more parf the projections of the cutters are embedded in the core. g

3. A die as claimed in claim 1, in which the cutters are fixed to. the core bybolts having no thread, the latter being fixed to the core by means of transverse pins entirely sunk into the core. i c

4. A die as claimed in claim 1,, in which at the narrow parts of the core, cutters are fixed to the same by fixing means extending; right through said core and clamping together two parts of the cutters and the core lying between them.

, 5. Adie as claimed in claim 1,. in which the cutter extends right round the core and is fixed to said core in a single piece.

-6. A die as claimed in claim 1, in which a veneered core is held together by screws fitted inthe core from both faces and staggered withrespect toone another.

7. A d ie as claimed in claim 1, in which a v the projections are in the form of fiat pieces connected with the cutter.

9. A die as claimed in claim 1, in which the projections are in the form of tongues bent out of the cutter material.

In Witness whereof I have hereunto signed my name.

FRANZ MERTINZ.

a compression spring 21. The other part 20 of the punch rests against an inwardly directed flange 22 and the spring against an inward- 1y bent part 23 of the sleeve19. The whole arrangement forms a complete unit which,

owing to the smooth surface of the sleeve 19, 

